From my experiments the following has been known:—
1. The starch-digesting power of the thermal water of each natural hot-spring in Beppu is lower in its proper PH than in its optimum PH of amylase brought about by use of the buffer solution.
2. The phenomenon of degeneration has been observed in the water of the majority of Beppu's hot-springs.
The digesting power of the water fresh from each spring diminishes gradually as it becomes older by being stored for a space of time. Furthermore, the same phenomenon is noticed in the stored old water restored to the former state in which it first gushed out from under the ground, by applying to it a high pressure of 4 atmospheres as well as by heating it to over 130°C, though there are some hot-spring whose water does not show at all this phenomenon of degeneration.
3. Thus, regeneration of the digesting power of the stored old water has been noted. But, whether this specific function is to be ascribed to the component water itself or to the contained chemical ingredient or ingredients, is yet to be ascertained.
It is hoped that my further experiments may lead to the final solution of this question.
(The present research is being conducted under the Education Ministry fund for scientific researches.)

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